There is conventionally used a refrigeration apparatus that carries out a multistage compression refrigeration cycle, being a refrigeration apparatus provided with means for cooling intermediate-pressure refrigerant in the course of compression. The refrigeration apparatus described in Japanese Laid-open Patent Application No. 2010-112618 has a heat source unit provided with an outdoor-side heat exchanger and an outdoor-side intermediate cooler. In the cooling operation, the outdoor-side heat exchanger functions as a gas cooler, and the outdoor-side intermediate cooler functions as an inter-cooler that cools intermediate-pressure refrigerant discharged from a preceding stage compression element and sucked into a subsequent stage compression element. Improved operating efficiency is realized in this refrigeration apparatus as intermediate-pressure refrigerant is cooled in the course of compression.